reminder - seeking data on Bell’s Vireos
- I posted this last fall... a reminder as we head into nesting season:
Sorry for any cross-postings, but to ensure a wide-distribution, please
forward this request to appropriate regional lists or to observers that
may not be on these lists -- especially those outside of California.
Least Bell's Vireo (Vireo bellii pusillus) populations underwent a
substantial crash in the mid-20th Century, resulting in a reduction in the
range of the subspecies. Populations are now rebounding and the subspecies
is re-colonizing areas within its former range. Researchers would like to
document the change in distribution of Least Bell's Vireos over time.
In general, at its nadir, the "core" of the Least Bell's Vireo population
was coastal San Diego County, California. By the 1990s populations had
spread such that the core could be considered to include Orange County and
western Riverside County. Today, it is not surprising to find Least Bell's
Vireos at quite a few sites outside that area; moreover, sightings in the
far north, although still far from commonplace, are no longer shocking.
Less is known about the status of the subspecies on the Baja California
Peninsula, but records of observations there are on the increase, in part
due to increased coverage and improved documentation/communication. Also,
Bell's Vireo observations in the eastern (transmontane) desert areas of
California and even western Nevada -- be they "Least" or "Arizona" Bell's
Vireos -- appear to have been poorly documented in the past, though
documentation appears to have improved recently.
We are asking willing field observers -- amateurs and professionals alike
-- to document past and future observations of Bell's Vireos in California,
the western edge of Nevada, and the Baja California Peninsula (unseasonal
occurrences too). Please dig through your notes for older records.
Additionally, many regional chroniclers of bird info have older records
that are not in the literature or are in obscure, regional sources. And
for those of you who did such things, please also consider submitting data
from older, unpublished survey reports that may not have withstood the
tests of time.
Additionally, many Bell’s Vireos are banded with unique combinations of
color bands. Please try to visually confirm your detections to see if
there are bands. If you see bands, note the combination of colors (top to
bottom, left leg and right leg [relative to the bird]). Please submit band
observations to the Bird Banding Lab and Dr. Barbara Kus (see URLs below).
Those of you who have been submitting survey data to Dr. Kus at USGS
Western Ecological Research Center (WERC) -- thank you, and please continue
to submit your data. There are also a number of ways for volunteers to
memorialize incidental observations. The California Natural Diversity
Database (CNDDB) is a long-standing resource with rigorous standards (see
URLs, below, for additional info). The newer eBird database is an
easy-to-use database with a geographical coverage that extends beyond
California that allows for both current and historical records (using the
"incidental" observation type). Also, please (continue to) submit current
and future "extralimital" and unseasonal sightings of Bell's Vireos to the
journal North American Birds. Please be as specific as possible when
submitting information, regardless of venue.
Useful webpage URLs:
eBird Calif: http://ebird.org/content/ca
NAB Regional Eds (CA): http://fog.ccsf.cc.ca.us/jmorlan/afn.html
NAB journal: http://www.aba.org/nab/
USGS WERC: http://www.werc.usgs.gov/
Dr. Kus (USGS): http://www.werc.usgs.gov/person.aspx?personID=18
Contact info for Dr. Barbara Kus
San Diego Field Station
4165 Spruance Road Suite 200
San Diego, CA 92101
Phone: (619) 225-6421
Fax: (619) 225-6436
Thank you for your assistance.
Gjon C. Hazard
Fish and Wildlife Biologist
Carlsbad Fish and Wildlife Office
6010 Hidden Valley Road, Suite 101
Carlsbad, CA 92011 USA
[Non-text portions of this message have been removed]